As electronic appliances, such as settop boxes, and their constituent components, such as front ends, become more complex, a wide variety of signals need to be supported. These signals include those used in satellite, cable, Multi-Media Coaxial (MoCA), terrestrial and other wired and/or wireless communication environments. One concern is the potential for interaction and possibly interference between the various signals over a wideband input frequency spectrum, prompting certain industry-recognized coexistence requirements. There exists a variety of solutions to meet or at least address such coexistence requirements, including the implementation of filters, diplexers, triplexers and/or frequency converters.
One particular concern in such systems is the reflection of signals at the input to certain components, such as at the input to a settop box comprising front end circuitry comprising an input port followed by a passband filter (and optionally a resistive pad). Typically, return loss in a filter passband is acceptable and provides proper circuit loading. In the filter stopband, however, the return loss becomes reflective and all or a significant portion of the signal energy is reflected back to the source. This reflection may cause a non-compliant broadband return loss issue at the input to, or at a component upstream of, the settop box or an unwanted reflected energy back into a component of another electronic appliance, such as a mixer or other circuit of a transceiver device or other signal source.